daemon: replace ErrExtractPointNotDirectory with errdefs
daemon: replace ErrExtractPointNotDirectory with errdefs

It was only used in a single location, and the ErrExtractPointNotDirectory was
not checked for, or used as a sentinel error.

This error was introduced in c32dde5baadc8c472666ef9d5cead13ab6de28ea. It was
never used as a sentinel error, but from that commit, it looks like it was added
as a package variable to mirror already existing errors defined at the package
level.

This patch removes the exported variable, and replaces the error with an
errdefs.InvalidParameter(), so that the API also returns the correct (400)
status code.

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

Mokolea/docker,moul/docker,thaJeztah/docker,Mokolea/docker,thaJeztah/docker,konstruktoid/docker-upstream,mahak/docker,trebonian/docker,moby/moby,moby/moby,moul/docker,jimjag/docker,jimjag/docker,konstruktoid/docker-upstream,cpuguy83/docker,mahak/docker,konstruktoid/docker-upstream,trebonian/docker,Mokolea/docker,Ramzec/docker,Ramzec/docker,thaJeztah/docker,trebonian/docker,moby/moby,Ramzec/docker,cpuguy83/docker,Mokolea/docker,moul/docker,moul/docker,jimjag/docker,Ramzec/docker,trebonian/docker,thaJeztah/docker,konstruktoid/docker-upstream,mahak/docker,cpuguy83/docker,mahak/docker,jimjag/docker,moby/moby,cpuguy83/docker